El actor guapo sonrió.

El is the masculine singular definite article, meaning the.

• el actor = the actor
• It agrees with actor, which is a masculine singular noun.

In Spanish, articles are used more regularly than in English, so el actor sounds natural and complete.

In Spanish, adjectives usually come after the noun.

So:

• el actor guapo = the handsome actor

Putting the adjective before the noun is sometimes possible, but it often changes the tone or emphasis. For a basic, neutral description, actor guapo is the normal order.

In Spain, guapo commonly means good-looking, handsome, or attractive.

In this sentence:

• el actor guapo = the handsome actor

Depending on context, guapo can sometimes also mean something like nice-looking rather than extremely handsome.

Because actor is a masculine noun, the adjective must match it in gender and number.

• masculine singular: guapo
• feminine singular: guapa
• masculine plural: guapos
• feminine plural: guapas

So:

• el actor guapo
• la actriz guapa

Sonrió is the preterite form of the verb sonreír.

It means:

• he smiled
• she smiled
• it smiled (depending on context)

The preterite is used for a completed action in the past, so sonrió tells us that the smiling happened as a finished event.

The accent mark shows where the stress goes and helps distinguish the pronunciation.

• sonrió is stressed on the final -ó
• It is pronounced roughly son-ree-O

Without the accent mark, Spanish spelling rules would suggest a different stress pattern. So the accent is important both for pronunciation and correct spelling.

Spanish often leaves out subject pronouns when they are not needed.

The verb form sonrió already tells you it is he/she/it in the preterite, so él is unnecessary unless you want emphasis or contrast.

So both are possible:

• El actor guapo sonrió. = normal
• Él sonrió. = He smiled, with more emphasis on he

Also note the difference:

• el = the
• él = he

It is not fully regular. Sonreír is a stem-changing verb in some forms, and it also has spelling/stress changes because of the -eír ending.

For example:

• sonrío = I smile
• sonríe = he/she smiles
• sonrió = he/she smiled

So it is a verb you should learn by pattern rather than treating as a completely regular -ir verb.

A simple pronunciation guide is:

el ak-TOR GWA-po son-ree-O

A few notes:

• actor: the c sounds like k
• guapo: gua sounds like gwa
• sonrió: the stress falls on the last syllable -ó

In Spain, pronunciation may vary slightly by region, but this guide is a good standard starting point.

Traditionally, actor is masculine, and the feminine form is actriz.

So:

• el actor = the male actor
• la actriz = the actress / female actor

In modern usage, some people may use actor more broadly in certain contexts, but for standard beginner Spanish, it is best to learn:

• actor = masculine
• actriz = feminine

Because guapo is directly attached to the noun phrase el actor.

The sentence structure is:

• El actor guapo = the handsome actor
• sonrió = smiled

So guapo describes who the actor is, not how he smiled.

If you wanted to describe the action, you would usually use an adverb instead of an adjective.

Yes. That is a very natural translation.

Because the meaning is already known, the main thing to notice is that Spanish does not force one exact English equivalent. Guapo could be translated as:

• handsome
• good-looking
• attractive

The best choice depends on context and style.